ORAU TEAM

Dose Reconstruction

Project for NIOSH

Oak Ridge Associated Universities I Dade Moeller I MJW Technical Services

Page 1 of 52

DOE Review Release 08/23/2012

Document Title:

A Comparison of Neptunium Coworker 

Models at the Savannah River Site

Document Number: ORAUT-RPRT-0056

Revision: 00

Effective Date: 08/20/2012

Type of Document: Report

Supersedes: None

Subject Expert(s): Matthew G. Arno, James M. Mahathy, and Nancy Chalmers

Approval: Signature on File Approval Date: 08/13/2012

Matthew G. Arno, Document Owner

Concurrence: Signature on File Concurrence Date: 08/14/2012

John M. Byrne, Objective 1 Manager

Concurrence: Signature on File Concurrence Date: 08/14/2012

Edward F. Maher, Objective 3 Manager

Concurrence: Vickie S. Short Signature on File for Concurrence Date: 08/14/2012

Kate Kimpan, Project Director

Approval: Signature on File Approval Date: 08/20/2012

James W. Neton, Associate Director for Science

New Total Rewrite Revision Page Change

FOR DOCUMENTS MARKED AS A TOTAL REWRITE, REVISION, OR PAGE CHANGE, REPLACE THE PRIOR 

REVISION AND DISCARD / DESTROY ALL COPIES OF THE PRIOR REVISION.
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 2 of 52

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

08/20/2012 00 New report initiated to evaluate Savannah River Site neptunium 

coworker models. Incorporates formal internal and NIOSH review 

comments. Training required: As determined by the Objective 

Manager. Initiated by Matthew G. Arno. 
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 3 of 52

TABLE OF CONTENTS

SECTION TITLE PAGE

Acronyms and Abbreviations ............................................................................................................... 6

1.0 Introduction .............................................................................................................................. 7

2.0 Bioassay Data versus Dose ..................................................................................................... 7

3.0 Methodology ............................................................................................................................ 8

3.1 Neptunium Bioassay Data ............................................................................................ 9

3.2 Job Classification Determination................................................................................. 10

3.3 One Person – One Sample Statistic ........................................................................... 12

3.4 Statistical Analysis...................................................................................................... 13

3.5 Strata Comparison...................................................................................................... 13

4.0 Results................................................................................................................................... 13

4.1 Bioassay Fitting .......................................................................................................... 13

4.2 Strata Comparisons.................................................................................................... 13

5.0 Conclusions ........................................................................................................................... 14

References ........................................................................................................................................ 15

ATTACHMENT A, ROS PLOTS FOR AMWS, CTW, NONCTWS, AND 

NONCTW+UNKS................................................................................................. 16

ATTACHMENT B, PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK 

COMPARISONS.................................................................................................. 43

LIST OF TABLES 

TABLE TITLE PAGE

3-1 Number of bioassay results per period – logbook data........................................................... 12

3-2 Number of bioassay results per period – NOCTS data........................................................... 12

3-3 Population and neptunium monitoring ratios........................................................................... 12

4-1 Strata comparison..................................................................................................................14

LIST OF FIGURES

FIGURE TITLE PAGE

A-1 ROS fit for AMW, 1961........................................................................................................... 16

A-2 ROS fit for AMW, 1962........................................................................................................... 16

A-3 ROS fit for AMW, 1963........................................................................................................... 17

A-4 ROS fit for AMW, 1974........................................................................................................... 17

A-5 ROS fit for AMW, 1975........................................................................................................... 18

A-6 ROS fit for AMW, 1977........................................................................................................... 18

A-7 ROS fit for AMW, 1978........................................................................................................... 19

A-8 ROS fit for AMW, 1979........................................................................................................... 19
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 4 of 52

A-9 ROS fit for AMW, 1980........................................................................................................... 20

A-10 ROS fit for AMW, 1981........................................................................................................... 20

A-11 ROS fit for AMW, 1983........................................................................................................... 21

A-12 ROS fit for AMW, 1984........................................................................................................... 21

A-13 ROS fit for AMW, 1985........................................................................................................... 22

A-14 ROS fit for AMW, 1986........................................................................................................... 22

A-15 ROS fit for AMW, 1987........................................................................................................... 23

A-16 ROS fit for AMW, 1988........................................................................................................... 23

A-17 ROS fit for AMW, 1989........................................................................................................... 24

A-18 ROS fit for CTW, 1961 ........................................................................................................... 24

A-19 ROS fit for CTWs, 1962 ......................................................................................................... 25

A-20 ROS fit for CTWs, 1963 ......................................................................................................... 25

A-21 ROS fit for CTWs, 1974 ......................................................................................................... 26

A-22 ROS fit for CTWs, 1975 ......................................................................................................... 26

A-23 ROS fit for CTWs, 1977 ......................................................................................................... 27

A-24 ROS fit for CTWs, 1978 ......................................................................................................... 27

A-25 ROS fit for CTWs, 1979 ......................................................................................................... 28

A-26 ROS fit for CTWs, 1980 ......................................................................................................... 28

A-27 ROS fit for CTWs, 1981 ......................................................................................................... 29

A-28 ROS fit for CTWs, 1983 ......................................................................................................... 29

A-29 ROS fit for CTWs, 1984 ......................................................................................................... 30

A-30 ROS fit for CTWs, 1985 ......................................................................................................... 30

A-31 ROS fit for CTWs, 1986 ......................................................................................................... 31

A-32 ROS fit for CTWs, 1987 ......................................................................................................... 31

A-33 ROS fit for CTWs, 1988 ......................................................................................................... 32

A-34 ROS fit for CTWs, 1989 ......................................................................................................... 32

A-35 ROS fit for nonCTWs, 1961.................................................................................................... 33

A-36 ROS fit for nonCTWs, 1962.................................................................................................... 33

A-37 ROS fit for nonCTWs, 1963.................................................................................................... 34

A-38 ROS fit for nonCTWs, 1974.................................................................................................... 34

A-39 ROS fit for nonCTWs, 1975.................................................................................................... 35

A-40 ROS fit for nonCTWs, 1977.................................................................................................... 35

A-41 ROS fit for nonCTWs, 1978.................................................................................................... 36

A-42 ROS fit for nonCTWs, 1979.................................................................................................... 36

A-43 ROS fit for nonCTWs, 1980.................................................................................................... 37

A-44 ROS fit for nonCTWs, 1981.................................................................................................... 37

A-45 ROS fit for nonCTWs, 1983.................................................................................................... 38

A-46 ROS fit for nonCTWs, 1984.................................................................................................... 38

A-47 ROS fit for nonCTWs, 1985.................................................................................................... 39

A-48 ROS fit for nonCTWs, 1986.................................................................................................... 39

A-49 ROS fit for nonCTWs, 1987.................................................................................................... 40

A-50 ROS fit for nonCTWs, 1988.................................................................................................... 40

A-51 ROS fit for nonCTWs, 1989.................................................................................................... 41

A-52 ROS fit for nonCTWs+unk, 1961............................................................................................ 41

A-53 ROS fit for nonCTWs+unk, 1962............................................................................................ 42

A-54 ROS fit for nonCTWs+unk, 1963............................................................................................ 42

B-1 Peto-Prentice test for CTW:nonCTW, 1961............................................................................ 43

B-2 Peto-Prentice test for CTW:nonCTW, 1962............................................................................ 43

B-3 Peto-Prentice test for CTW:nonCTW, 1963............................................................................ 44

B-4 Peto-Prentice test for CTW:nonCTW, 1974............................................................................ 44

B-5 Peto-Prentice test for CTW:nonCTW, 1975............................................................................ 45

B-6 Peto-Prentice test for CTW:nonCTW, 1977............................................................................ 45

B-7 Peto-Prentice test for CTW:nonCTW, 1978............................................................................ 46
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 5 of 52

B-8 Peto-Prentice test for CTW:nonCTW, 1979............................................................................ 46

B-9 Peto-Prentice test for CTW:nonCTW, 1980............................................................................ 47

B-10 Peto-Prentice test for CTW:nonCTW, 1981............................................................................ 47

B-11 Peto-Prentice test for CTW:nonCTW, 1983............................................................................ 48

B-12 Peto-Prentice test for CTW:nonCTW, 1984............................................................................ 48

B-13 Peto-Prentice test for CTW:nonCTW, 1985............................................................................ 49

B-14 Peto-Prentice test for CTW:nonCTW, 1986............................................................................ 49

B-15 Peto-Prentice test for CTW:nonCTW, 1987............................................................................ 50

B-16 Peto-Prentice test for CTW:nonCTW, 1988............................................................................ 50

B-17 Peto-Prentice test for CTW:nonCTW, 1989............................................................................ 51

B-18 Peto-Prentice test for CTW:nonCTW+unk, 1961.................................................................... 51

B-19 Peto-Prentice test for CTW:nonCTW+unk, 1962.................................................................... 52

B-20 Peto-Prentice test for CTW:nonCTW+unk, 1963.................................................................... 52
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 6 of 52

ACRONYMS AND ABBREVIATIONS

AMW all monitored workers

cm centimeter

cpm counts per minute

CTW construction trade worker

d day

GM geometric mean

GSD geometric standard deviation

ID identification

L liter

MCPT Monte Carlo permutation test

MDA minimum detectable activity

MPM maximum possible mean

nCi nanocurie

NIOSH National Institute for Occupational Safety and Health

NOCTS NIOSH Claims Tracking System

OPOS one person – one sample

ORAU Oak Ridge Associated Universities

ROI region of interest

ROS regression on order statistics

SRDB Ref ID Site Research Database Reference Identification (number)

SRS Savannah River Site

TLD thermoluminescent dosimeter

unk unknown

WBC whole-body count
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 7 of 52

1.0 INTRODUCTION

At the Savannah River Site (SRS), some workers might have been exposed to neptunium without 

being monitored for that potential exposure. The National Institute for Occupational Safety and Health 

(NIOSH) Dose Reconstruction Project uses coworker models to estimate doses to workers who were 

not monitored for exposure to radioactive materials but might have been exposed to such materials 

(ORAUT 2007, p. 13). Such a dose is referred to as an unmonitored dose. Coworker models are 

typically constructed using data from all monitored workers by fitting a lognormal probability 

distribution to the data (ORAUT 2005, 2006) to estimate the geometric mean (GM) and geometric 

standard deviation (GSD) of the doses. Coworker models for external dose are usually constructed 

from external doses assigned to individuals with film badges and thermoluminescent dosimeters 

(TLDs). Coworker models for internal dose are calculated using bioassay data that are later 

evaluated in terms of chronic intake rates and, ultimately, internal doses.

Rather than using all monitored workers to construct a coworker model, an analysis can stratify 

monitored workers into subgroups (i.e., strata) and construct separate coworker models for each 

stratum. Stratification offers potential advantages, such as more precise estimates of the dose to 

unmonitored workers in a stratum, but it has a number of potential drawbacks and limitations (ORAUT 

2010). The purpose of this report is to evaluate two proposed strata in relation to bioassay data,

potential intakes, and internal doses of neptunium. The two strata consist of (1) the construction trade 

worker (CTW) stratum, which includes workers classified as CTWs in accordance with ORAUT-OTIB0052 (ORAUT 2011) and (2) the nonCTW stratum, which includes workers not classified as CTWs

(non-construction trade workers). A statistically and practically significant difference between the 

CTW and nonCTW strata could warrant coworker models based on the individual strata rather than 

the entire population of monitored workers, designated as all monitored workers (AMW) in this report.

This evaluation includes a third stratum of workers whose job classifications are not available or 

unknown (abbreviated as unk). This is different from the application of ORAUT-OTIB-0052 (ORAUT 

2011) during performance of dose reconstructions in which individuals are not considered to be CTWs 

unless there is a reason to classify them as such. In this analysis, unks are evaluated in two ways: (1)

they are included with the nonCTWs, and (2) they are excluded entirely from the strata comparison. 

Exclusion of bioassay data from the strata comparison is the difference from the normal application of 

ORAUT-OTIB-0052. The distinction is made for this report because less information is available 

about all the workers with neptunium bioassay data than is available for energy employees whose 

dose is being reconstructed. For energy employees whose dose is being reconstructed, individualspecific information is available from U.S. Department of Energy records, the record of the telephone 

interview, and information provided by the U.S. Department of Labor.

2.0 BIOASSAY DATA VERSUS DOSE

Monitoring for workers who have the potential for exposure to external radiation typically consists of a 

dosimeter (e.g., TLD or film badge) worn on the upper torso of the body. The dosimeter indicates the 

cumulative dose to the whole body that is received between readings, which creates monitoring 

intervals that can be days to months in duration. A key property of the reported doses for each 

interval is that, for a given individual, the doses are statistically independent of each other. For 

example, the received dose in a given month, by itself, provides no information about the dose in the 

next month and, similarly, the received dose in a given year, by itself, provides no information about 

the dose in the next year.

Internal dose monitoring programs are in many ways similar to the above-described external dose 

programs, but internal dose programs tend to be based on bioassay rather than dosimeters. This is 

an important difference because, if an individual has an intake of radioactive material such that 

radioactive material is detected in a given sample, subsequent bioassay samples can also have 
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 8 of 52

detectable radioactivity even if there have been no additional intakes. This means bioassay results 

can correlate to each other and are no longer statistically independent. This correlation can exist for a 

brief period (after a small intake of tritium, for example), or for the length of a career (after a large 

intake of plutonium, for example).

Operational bioassay programs can generate multiple results for an individual in a given period (e.g., 

a year), which creates a related problem if an individual is involved in an incident and has more 

(potentially many more) bioassay results than other workers. If these are not accounted for, the 

problems of correlated data and unequal numbers of samples per person can skew evaluation of the 

data by unequally weighting data from that individual. The solution to this problem is to generate a 

single statistic that characterizes multiple bioassay results for each person in a given period. This is 

referred to as a one person – one sample (OPOS) statistic. The OPOS statistic is calculated using 

the maximum possible mean (MPM) methodology (ORAUT 2012).

3.0 METHODOLOGY

The CTW and nonCTW strata were compared using the methodology from ORAUT-RPRT-0053 

(ORAUT 2012). The basic steps of this methodology, discussed in more detail below, are:

• Evaluate the complete set of neptunium bioassay data and determine the job classification 

(CTW, nonCTW, or unk) for each individual for each bioassay sample.

• For each individual and each period, determine the OPOS statistic for the AMW, CTW, and 

nonCTW strata, and for the combined nonCTW+unk stratum (see Section 4.1 for more detail).

• Determine the GM and GSD urinary excretion rates for the AMW, CTW, nonCTW, and 

combined nonCTW+unk strata for each period using the regression on order statistics (ROS), 

effective fit, and binomial methods (ORAUT 2012) as appropriate.

• Compare the CTW:nonCTW and CTW:nonCTW+unk strata using the Monte Carlo permutation 

test (MCPT) and Peto-Prentice test (ORAUT 2012) to determine if there is a statistically 

significant difference.

• If there is a statistically significant difference, compare the CTW:nonCTW and 

CTW:nonCTW+unk strata to determine if there is a practical difference.

At Savannah River, all personnel working in regulated areas (“Regulated Zones” and “Radiation 

Danger Zones”), including construction workers, were periodically checked for assimilation of 

radioactive material by urinalysis bioassay (DuPont 1961-1969). The only exception to this may have 

been when special exclusion zones were established, and when this occurred, the outer boundaries 

of the radiological areas were monitored (ORAUT 2008). Notification of sample request was given to 

employees through their supervision. Special bioassay samples were requested of workers, including 

construction workers, by Health Physics through the worker’s supervision, when a potential 

assimilation of radioactive material was suspected (DuPont 1961-1969).

CTWs are potentially subject to different bioassay practices than other workers. CTWs, many of 

whom are contractors, commonly submit bioassay samples after suspected uptakes and at the 

completion of jobs. This is in contrast to other workers, especially those employed directly by the 

prime contractor, who are more likely to be on a routine bioassay program in addition to submitting 

bioassay samples after suspected uptakes. A post-job bioassay is more likely to be soon after an 

uptake, either suspected or unidentified, than is a routine bioassay sample and thus more likely to 

have a larger result. This potential difference in how the strata are monitored for intakes would result 

in higher results for CTWs compared to the other strata.
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 9 of 52

3.1 NEPTUNIUM BIOASSAY DATA

Neptunium urinalysis bioassay data were obtained from SRS laboratory notebooks (DuPont 1961-

1969, 1969) and from NIOSH Claims Tracking System (NOCTS) records for years after 1969. The 

laboratory notebook data were transferred to a spreadsheet and subjected to a 100% verification 

review by a second person. Records with results or units of “LIP” (Lost In Process) or “IA” (Insufficient 

Amount) were excluded from the evaluation because those records represent instances in which

samples were collected but not analyzed. Records with units of per-unit-volume were adjusted to 

“per-1.5L” based on an assumed 1.5 L/d of urinary excretion. Volumes greater than 1 L were 

assumed to represent a full day’s voiding and were not adjusted. Volumes less than or equal to 1 L

were normalized to 1.5 L. 

In the absence of site logbooks and databases after 1969, NOCTS whole-body count (WBC) data 

were selected as the best available compilation of data in a usable form. The NOCTS database was 

queried on May 7, 2008, to generate a list of all claimants who worked at SRS before 1991. This 

amounted to 1,421 individuals. Data for six additional individuals that became available during the 

data entry process were added for a total of 1,427 individuals. The NOCTS ID numbers of the 

specific individuals identified are listed in Arno (2011). Table 2 of this reference lists NOCTS ID 

numbers of the 923 individuals identified as having in vivo bioassay data during this time frame. The 

in vivo bioassay data for these individuals, 923 of which had WBC data, were entered into 

spreadsheets (some already existed in this form after the completion of dose reconstructions for 

individuals). The spreadsheets were subjected to a quality assurance (QA) verification in accordance 

with MIL-STD-105E, Sampling Procedures and Tables for Inspection by Attributes (DOD 1989), which 

it passed with less than a 1% error rate. For this QA verification, 315 records (out of the 33,088 total 

records) were checked with only 1 error found. Per MIL-STD-105E (DOD 1989), for a lot between 

10,001 and 35,000 items, less than 8 errors results in lot acceptance based upon the statistical 

variability of sampling. 

Most WBC reports in NOCTS do not quantify 237Np body burdens or report a minimum detectable 

activity (MDA). However, some reporting methods provide sufficient information to determine or 

estimate the 237Np body burden. Methods were developed to estimate 237Np for three of the different 

reporting forms used. These methods use the fact that a region of interest (ROI) used to report 

activity for radionuclides other than 237Np would also be reporting activity from 237Np or its decay 

product, 233Pa. Protactinium-233 has principal gammas of 312 keV (39% yield) and 300 keV (6.6% 

yield). By assuming that all the reported counts or count rate in the ROI is due to 237Np rather than 

other radionuclides, the 237Np may be estimated.

The first form, “Whole Body Counter Data,” was in use from approximately 1960 through the mid1970s and was used with the 40-cm arc geometry (Taylor et al. 1995, p. 64). Results for nuclides 

other than 137Cs and 40K were reported in units of count rate (net counts per minute) rather than 

activity. This form reports count rates for 131I based on the net counts in the ROI from 300 to 400 keV. 

Protactinium-233 has several gammas that fall totally or partially in that energy range – 300 keV 

(6.6%), 312 keV (38.6%), 340 keV (4.5%), 375 keV (0.6%), and 399 keV (1.27%) (Kocher 1981). The 

300- and 399-keV peaks would fall half-out and half-in of the ROI, respectively, so in effect those 

abundances are only half of the stated values. Thus, the total gamma abundance in the 300-to-400-

keV ROI for 233Pa is 47.6%. It is possible to use the reported net cpm for 131I to estimate the 237Np

body burden by assuming that all the net cpm in the 131I ROI is due to 237Np. The conversion factor 

from net counts in the 131I ROI to nanocuries of 237Np is 0.243 nCi/cpm. This conversion factor was 

determined by adjusting the 137Cs calibration factor of 0.136 nCi/cpm (Watts1962-1967, p. 33) for the 

gamma abundances of 137Cs and 233Pa in their respective ROIs: (0.136)(0.85) ÷ 0.476. To refine the 

estimate, it is necessary to account for the Compton continuum contribution to the 131I ROI from the 

40K body burden. The 40K contribution to the 131I ROI is 0.389 counts per 40K ROI net count (Watts 

1962-1967, p. 33). Thus, the 237Np body burden can be calculated as: 
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 10 of 52

( ) ( ) 237 131 40 nCi Np = 0.243 I net cpm 0.389 K net cpm × −×     (1)

The second reporting form is an untitled form used in the mid- and late 1970s. It is distinguishable by 

having the date, time, and name on successive lines on the left margin at the top of the form. This 

form also reports counts in the 300-to-400-keV ROI but does not associate this ROI with a particular 

radionuclide. For each ROI, gross, background, net, CALC, and DIFF values are reported. The 

CALC and DIFF values correct the net counts to account for Compton scatter, with the CALC value 

being the Compton scatter contribution and the DIFF value being the net counts minus CALC. 

Therefore, when using these data, there is no need to apply a 40K Compton scatter as with the Whole 

Body Counter Data form. When the 40-cm arc geometry was being used, assumed to be the period 

before February 1974, the 237Np body burden can be calculated as:

237 nCi Np = 0.243 (DIFF counts for 300-to-40 × 0-keV ROI) (2)

After January 1974, when the stretcher geometry was in use, the conversion factor changes (Fleming 

1973-1979, p. 162) and the 237Np body burden can be calculated as:

237 nCi Np = 0.0125 (DIFF counts for 300-to × -400-keV ROI) (3)

The third reporting form is the “In-Vivo Count Results” form, which was in use from the late 1970s 

through the late 1980s. The ROI on this form applicable to determine 237Np is the 51Cr ROI covering 

the energy range from 290 to 349 keV. This form also reports DIFF values; in addition, it reports the 

MDA in units of nanocuries and counts. Having the MDA reported in both manners permits the 

determination of a count-specific conversion factor from counts to nanocuries. The remaining step is 

the ratio of the conversion factor for 51Cr to that for 233Pa, which is 0.211 (based on the ratio of gamma 

abundances in the 51Cr ROI: 0.098 to 0.465). Therefore, the 237Np body burden can be calculated as:

237 51 51 51 nCi Np = 0.211 ( Cr DIFF counts) ( Cr MDA × ×÷ nCi) ( Cr MDA counts) (4)

3.2 JOB CLASSIFICATION DETERMINATION

NIOSH directed the Oak Ridge Associated Universities (ORAU) Team to use 1954 Craft Payroll 

Codes (Author unknown undated) as the source of crafts and occupations and the payroll ID field to 

determine workers that should be assigned to the CTW stratum. NIOSH and the ORAU Team 

reviewed the crafts in that document and determined that the following are CTW crafts at SRS that 

could have involved radiological exposure. The payroll ID prefix is listed with each of the crafts:

• 02 – Instruments (considered electricians)

• 05 – Laborer

• 06 – Carpenter

• 12 – Iron Worker

• 14 – Heavy Equipment Operator

• 15 – Steelworker

• 18 – Millwright

• 20 – Boilermaker

• 21 – Sheetmetal Worker

• 25 – Electrician

• 26 – Pipefitter

• 31 – Insulator

• 33 – Painter
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 11 of 52

In addition, NIOSH and the ORAU Team considered any worker in Payroll Roll #2 (which is different 

from payroll prefix 02 in the list above) with one of the craft (occupational title) listings above to be a 

CTW. An additional craft code, 17, was not in 1954 Craft Payroll Codes but was determined to be 

associated with “Painter” from examination of SRS work history data. Worker history cards were 

reviewed to determine the payroll ID number or occupational title for each individual for each bioassay 

result. The last entry on the worker history card before the date of the bioassay was used to 

determine the payroll ID number or occupational title.

The following steps were used to create a spreadsheet and identify CTW, nonCTW, and unk data. 

For each bioassay record, the ORAU Team used the sample date, name, and payroll ID (PR ID) to 

retrieve the assigned job/ occupational title from the SRS work history card matched to the sampled 

worker and for the sampled date because a worker could have multiple occupational titles over time. 

In some instances, the value of the PR ID field was different on the card than in the bioassay file and 

was changed in the spreadsheet used for this evaluation. Occupational titles were recorded as stated 

on the card. If the personal information could not be found in the SRS worker history cards or if an 

occupational title was not recorded on the matched card, “Unknown” was recorded in the 

Occupational Title field. Once occupational titles had been queried for all bioassay records, instances 

of the same high-level occupational title were made consistent and recorded in the Changed 

Occupational Title field. For example, Research Chemist and Junior Chemist were considered to be 

Chemist. The values of two fields, “Changed Payroll ID#” and “Changed Occupational Title,” were 

used to denote the value of the CTW field in that particular row. The name of these fields includes 

“changed” to distinguish them from the original payroll ID number and occupation title fields. The 

“changed Payroll ID #” field reformats the originally recorded payroll ID numbers into a consistent 

format (hyphens, leading zeros, etc.) while retaining the originally recorded number. No distinction 

was made between DuPont and non-DuPont workers.

1. If the Changed Payroll ID number was of the form “XX-ppppp” where “XX” is 02, 05, 06, 12, 

14, 15, 17, 18, 20, 21, 25, 26, 31, or 33 and “ppppp” is a 5- or more digit number, the record 

was treated as that of a CTW.

2. If the Changed Payroll ID number was of the form “T-nnnn” where “nnnn” is a number, the 

record was treated as that of a nonCTW. [Payroll IDs starting with “T-“ indicate payroll 1, 

which did not apply to CTWs.]

3. If the Changed Payroll ID number was of the form “mmmmm” where “mmmmm” is a 2-, 3-, 4-, 

or 5-digit number only, the value of Changed Occupational Title was checked.

a. If the Changed Occupational Title was Boilermaker, Carpenter, CTW, Electrician, Glass 

Blower, Heavy Equipment Operator, Helper, Laborer, Maintenance, Mechanic, Millwright, 

Painter, or Rigger, the record was treated as that of a CTW.

b. If the Changed Occupational Title was Roll 2, unknown, or null, the value of CTW was set 

to unk.

c. For all remaining rows, the record was treated as that of a nonCTW.

4. All remaining records were treated as unk.

Only bioassay data from the laboratory notebooks contain unknowns. Sufficient data were available 

for all NOCTS-sourced bioassay data to classify the worker.
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 12 of 52

3.3 ONE PERSON – ONE SAMPLE STATISTIC

An average bioassay result using the MPM method was determined for each individual for each 

evaluated period and each job category. This resulted in a table of OPOS results for AMW that used 

all available bioassay data and three other tables for the CTW, nonCTW, and nonCTW+unk strata 

that used only bioassay data identified as belonging to each of those strata. Because it was possible 

for a worker to change jobs during the course of a single evaluated period, it is possible that a worker 

would have some samples identified as nonCTW and others as CTW in the same period. Therefore, 

one person might have as many as four different OPOS results, one each for the AMW, CTW, 

nonCTW, and nonCTW+unk strata.

Tables 3-1 and 3-2 detail the percentage of occurrences of multiple bioassay results averaged using 

the MPM method for each stratum for logbook and NOCTS data respectively.

Table 3-1. Number of bioassay results per period – logbook data.

No. of bioassay 

results

AMW

(%)

CTW

(%)

nonCTW

(%)

nonCTW+unk

(%)

1 64.2 60.6 64.5 65.1

2 22.2 26.7 21.5 21.2

3 6.8 5.2 7.4 7.3

>3 6.8 7.5 6.6 6.5

Table 3-2. Number of bioassay results per

period – NOCTS data.

No. of bioassay 

results

AMW

(%)

CTW

(%)

nonCTW

(%)

1 72.7 80.7 71.6

2 20.9 16.1 22.3

3 2.8 0.7 3.1

>3 3.6 2.6 2.9

Table 3-3 lists the ratio of CTWs and nonCTWs that received whole body counts from which potential

neptunium body burdens were reconstructed for each year in the 1973 through 1981 time period. The 

number of manufacturing and technical workers (assumed to represent the nonCTWs) and the 

number of construction workers is based on the SRS monthly report abstracts prepared by Taulbee 

(2011) using the number of manufacturing, technical, and construction workers summarized for July of 

each year. There is no significant difference between the population and bioassay monitoring ratios 

for the two groups, which is consistent with the implementation of the same radiological monitoring 

procedures for the two groups.

Table 3-3. Population and neptunium monitoring ratios.

Year # nonCTW+unks # CTWs Population 

Ratio

Bioassay 

Ratio

1973 5255 500 0.10 0.09

1974 5205 600 0.12 0.17

1975 5140 973 0.19 0.33

1976a 5407 995 0.18 0.86

1977 5598 1344 0.24 0.26

1978 5944 1973 0.33 0.26

1979 5709 1958 0.34 0.22

1980 6050 1991 0.33 0.22

1981 6593 2159 0.33 0.23

a. Very little bioassay data are available for 1976 resulting in anomalous ratios for this

 year. 
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 13 of 52

3.4 STATISTICAL ANALYSIS

Statistical analysis of each dataset was performed in accordance with ORAUT-RPRT-0053 (ORAUT 

2012). First, each period was evaluated using the ROS method. If this method failed or yielded an 

unacceptable fit, the effective fit (maximum likelihood) method would be used. If there was little or no 

uncensored data, the binomial fit method would be used. For this report, the ROS method was 

ultimately used for all evaluated years. For the CTW strata based on logbook data, some years 

(1964, 1965, 1967, 1968, and 1969) had insufficient data even to use the binomial fit and were not 

evaluated. 

3.5 STRATA COMPARISON

For each period, the CTW stratum was compared to both the nonCTW and nonCTW+unk strata to 

determine if there were statistical differences at the 0.05 level of significance. Presence of a 

statistically significant difference was determined using the MCPT and the Peto-Prentice test. If the 

amount of data was so small that no evaluation was possible, no strata comparison was made 

because insufficient information was available.

4.0 RESULTS

4.1 BIOASSAY FITTING

Two sets of comparisons were made. The first set compared the CTW and nonCTW strata. The 

second set compared the CTW and combined nonCTW+unk strata. The unk stratum was included 

with the nonCTW stratum because this was the default assumption. Workers were assumed to 

belong to the nonCTW stratum unless there was justification to include them in the CTW stratum.

For the AMW and each of the three strata, the ROS fit was calculated for all periods for which there 

were sufficient data (i.e., more than one uncensored result). No fit was done for 1964, 1965, 1967, 

1968, and 1969 because there were insufficient CTW data for those years. Attachment A contains 

the plots of the ROS fits for each stratum (including AMW).

4.2 STRATA COMPARISONS

For 1964 to 1973, 1976, and 1982, there were insufficient data to perform a comparison between the 

strata in either comparison set. The MCPT would not run for most of the years because of highly 

censored data. Almost all of the MCPT plots produced asymmetric clouds of points that were clearly 

not bivariate normal and nonparametric bagplots were not adequate, so MCPT analysis is not 

included. Sufficient data were available for all NOCTS-sourced bioassay data (1970 through 1989) to 

classify the worker as CTW or nonCTW and thus there are no unknowns in this time period. The 

Peto-Prentice test is used to determine whether the distribution of the OPOS bioassay data is the 

same in the CTW stratum and the nonCTW stratum (or the nonCTW stratum with unknowns). For the 

Peto-Prentice test, the result is a two-sided p-value. If the p-value is less than 0.05, the strata are 

considered different at a statistically significant level. Table 4-1 contains the results of these tests for 

the two comparison sets. Attachment B contains the plotted results of the Peto-Prentice tests. No 

multiple comparisons adjustments were needed, because no statistically significant differences were 

identified. Therefore, no evaluation of practical difference was performed.
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 14 of 52

 Table 4-1. Strata comparison.

 

Period CTW:nonCTW CTW:nonCTW+unka

1961 0.243 0.213

1962 0.899 0.789

1963 0.075 0.057

1974 0.876 N/A

1975 0.075 N/A

1977 0.975 N/A

1978 0.516 N/A

1979 0.666 N/A

1980 0.821 N/A

1981 0.310 N/A

1983 0.235 N/A

1984 0.850 N/A

1985 0.441 N/A

1986 0.685 N/A

1987 0.445 N/A

1988 0.142 N/A

1989 0.288 N/A

a. There are no unknowns in 1970 through 1989 and thus no difference 

 between the nonCTW and nonCTW+unk strata. Comparison with the 

 CTW strata would be identical and therefore was not repeated.

5.0 CONCLUSIONS

Statistical analysis revealed that the CTW stratum did not differ from the nonCTW or nonCTW+unk 

strata in a statistically significant manner for any periods with sufficient data. Therefore, there would 

be no benefit in evaluating the CTW stratum separately from other site worker strata and the SRS 

internal dose coworker study should evaluate neptunium intakes based on the AMW data.
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 15 of 52

REFERENCES

Arno, M., 2011, “NOCTS ID numbers used in the SRS Internal Coworker Study.” Oak Ridge 

Associated Universities, Oak Ridge, Tennessee, February 24. [SRDB Ref ID: 92815]

Author unknown, undated, 1954 Craft Payroll Codes. [SRDB Ref ID: 102063]

DOD (U.S. Department of Defense), 1989, Sampling Procedures and Tables for Inspection by 

Attributes, MIL-STD-105E, Washington, D.C., May 10. [SRDB Ref ID: 24964]

DuPont (E. I. du Pont de Nemours and Company), 1961–1969, Special Product Log Records 2-16-

1961 to 10-13-1969, Savannah River Site, Aiken South Carolina. [SRDB Ref ID: 51953]

DuPont (E. I. du Pont de Nemours and Company), 1969, Pu & Np Record Book, 4-8-1969, Savannah 

River Site, Aiken South Carolina. [SRDB Ref ID: 51973]

Fleming, R. R., 1973-1979, “R. R. Fleming Lab Notebook,” DPSTN-2011, E. I. Du Pont de Nemours 

and Company, Savannah River Laboratory, Aiken, South Carolina. [SRDB Ref ID: 61649]

Kocher, D. C., 1981, Radioactive Decay Data Tables: A Handbook of Decay Data for Application to 

Radiation Dosimetry and Radiological Assessments, DOE/TIC-11026, U.S. Department of 

Energy, Office of Scientific and Technical Information, Washington, D.C. [SRDB Ref ID: 

32563]

ORAUT (Oak Ridge Associated Universities Team), 2005, Analysis of Coworker Bioassay Data for 

Internal Dose Assessment, ORAUT-OTIB-0019, Rev. 01, Oak Ridge, Tennessee, October 7.

ORAUT (Oak Ridge Associated Universities Team), 2006, Generating Summary Statistics for 

Coworker Bioassay Data, ORAUT-PROC-0095, Rev. 00, Oak Ridge, Tennessee, June 5.

ORAUT (Oak Ridge Associated Universities Team), 2007, Internal Dose Reconstruction, ORAUTOTIB-0060, Rev. 00, Oak Ridge, Tennessee, February 6.

ORAUT (Oak Ridge Associated Universities Team), 2010, Discussion of Tritium Coworker Models at 

the Savannah River Site – Part 1, ORAUT-RPRT-0049, Rev. 00, Oak Ridge, Tennessee, 

November 23.

ORAUT (Oak Ridge Associated Universities Team), 2011, Parameters to Consider When Processing 

Claims for Construction Trade Workers, ORAUT-OTIB-0052, Rev. 01, Oak Ridge, Tennessee, 

February 17.

ORAUT (Oak Ridge Associated Universities Team), 2012, Analysis of Stratified Coworker Datasets, 

ORAUT-RPRT-0053, Rev. 01, Oak Ridge, Tennessee, January 16.

Taulbee, T., 2011, Notes on Savannah River Site personnel data for 1973-1982, National Institute for 

Occupational Safety and Health, Cincinnati, Ohio, September 25. [SRDB Ref ID: 105659]

Taylor, G. A., K. W. Crase, T. R. La Bone, and W. H. Wilkie, 1995, A History of Personnel Radiation 

Dosimetry at the Savannah River Site, WSRC-RP-95-234, Westinghouse Savannah River 

Company, Aiken, South Carolina, May. [SRDB Ref ID: 10931]

Watts, J. R., 1962-1967, “J. R. Watts Lab Notebook,” E. I. Du Pont de Nemours and Company, 

Savannah River Laboratory, Aiken, South Carolina. [SRDB Ref ID: 61711]
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 16 of 52

Figure A-1. ROS fit for AMW, 1961.

Figure A-2. ROS fit for AMW, 1962.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 1 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 17 of 52

Figure A-3. ROS fit for AMW, 1963.

Figure A-4. ROS fit for AMW, 1974.

ATTACHMENT A

ROS AND EFFECTIVE FIT PLOTS FO

Page 1 of 27

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 2 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 18 of 52

Figure A-5. ROS fit for AMW, 1975.

Figure A-6. ROS fit for AMW, 1977.

ATTACHMENT A

ROS AND EFFECTIVE FIT PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 2 of 27

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 3 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 19 of 52

Figure A-7. ROS fit for AMW, 1978.

Figure A-8. ROS fit for AMW, 1979.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 4 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 20 of 52

Figure A-9. ROS fit for AMW, 1980.

Figure A-10. ROS fit for AMW, 1981.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 5 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 21 of 52

Figure A-11. ROS fit for AMW, 1983.

Figure A-12. ROS fit for AMW, 1984.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 6 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 22 of 52

Figure A-13. ROS fit for AMW, 1985.

Figure A-14. ROS fit for AMW, 1986.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 7 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 23 of 52

Figure A-15. ROS fit for AMW, 1987.

Figure A-16. ROS fit for AMW, 1988.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 8 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 24 of 52

Figure A-17. ROS fit for AMW, 1989.

Figure A-18. ROS fit for CTWs, 1961.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 9 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 25 of 52

Figure A-19. ROS fit for CTWs, 1962.

Figure A-20. ROS fit for CTWs, 1963.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 10 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 26 of 52

Figure A-21. ROS fit for CTWs, 1974.

Figure A-22. ROS fit for CTWs, 1975.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 11 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 27 of 52

Figure A-23. ROS fit for CTWs, 1977.

Figure A-24. ROS fit for CTWs, 1978.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 12 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 28 of 52

Figure A-25. ROS fit for CTWs, 1979.

Figure A-26. ROS fit for CTWs, 1980.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 13 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 29 of 52

Figure A-27. ROS fit for CTWs, 1981.

Figure A-28. ROS fit for CTWs, 1983.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 14 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 30 of 52

Figure A-29. ROS fit for CTWs, 1984.

Figure A-30. ROS fit for CTWs, 1985.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 15 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 31 of 52

Figure A-31. ROS fit for CTWs, 1986.

Figure A-32. ROS fit for CTWs, 1987.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 16 of 27

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 16 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 32 of 52

Figure A-33. ROS fit for CTWs, 1988.

Figure A-34. ROS fit for CTWs, 1989.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 17 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 33 of 52

Figure A-35. ROS fit for nonCTWs, 1961.

Figure A-36. ROS fit for nonCTWs, 1962.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 18 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 34 of 52

Figure A-37. ROS fit for nonCTWs, 1963.

Figure A-38. ROS fit for nonCTWs, 1974.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 19 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 35 of 52

Figure A-39. ROS fit for nonCTWs, 1975.

Figure A-40. ROS fit for nonCTWs, 1977.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 20 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 36 of 52

Figure A-41. ROS fit for nonCTWs, 1978.

Figure A-42. ROS fit for nonCTWs, 1979.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 21 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 37 of 52

Figure A-43. ROS fit for nonCTWs, 1980.

Figure A-44. ROS fit for nonCTWs, 1981.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 22 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 38 of 52

Figure A-45. ROS fit for nonCTWs, 1983.

Figure A-46. ROS fit for nonCTWs, 1984.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 23 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 39 of 52

Figure A-47. ROS fit for nonCTWs, 1985.

Figure A-48. ROS fit for nonCTWs, 1986.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 24 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 40 of 52

Figure A-49. ROS fit for nonCTWs, 1987.

Figure A-50. ROS fit for nonCTWs, 1988.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 25 of 27

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 25 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 41 of 52

Figure A-51. ROS fit for nonCTWs, 1989.

Figure A-52. ROS fit for nonCTWs+unk, 1961.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 26 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 42 of 52

Figure A-53. ROS fit for nonCTWs+unk, 1962.

Figure A-54. ROS fit for nonCTWs+unk, 1963.

ATTACHMENT A

ROS PLOTS FOR AMWS, CTW, NONCTWS, AND NONCTW+UNKS

Page 27 of 27
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 43 of 52

Figure B-1. Peto-Prentice test for CTW:nonCTW, 1961.

Figure B-2. Peto-Prentice test for CTW:nonCTW, 1962.

ATTACHMENT B

MCPT AND PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK 

COMPARISONS

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 1 of 10
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 44 of 52

Figure B-3. Peto-Prentice test for CTW:nonCTW, 1963.

Figure B-4. Peto-Prentice test for CTW:nonCTW, 1974.

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 2 of 10
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 45 of 52

Figure B-5. Peto-Prentice test for CTW:nonCTW, 1975.

Figure B-6. Peto-Prentice test for CTW:nonCTW, 1977.

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 3 of 10
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Figure B-7. Peto-Prentice test for CTW:nonCTW, 1978.

Figure B-8. Peto-Prentice test for CTW:nonCTW, 1979.

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 4 of 10
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Figure B-9. Peto-Prentice test for CTW:nonCTW, 1980.

Figure B-10. Peto-Prentice test for CTW:nonCTW, 1981.

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 5 of 10
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 48 of 52

Figure B-11. Peto-Prentice test for CTW:nonCTW, 1983.

Figure B-12. Peto-Prentice test for CTW:nonCTW, 1984.

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 6 of 10
Document No. ORAUT-RPRT-0056 Revision No. 00 Effective Date: 08/20/2012 Page 49 of 52

Figure B-13. Peto-Prentice test for CTW:nonCTW, 1985.

Figure B-14. Peto-Prentice test for CTW:nonCTW, 1986.

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 7 of 10
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Figure B-15. Peto-Prentice test for CTW:nonCTW, 1987.

Figure B-16. Peto-Prentice test for CTW:nonCTW, 1988.

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 8 of 10
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Figure B-17. Peto-Prentice test for CTW:nonCTW, 1989.

Figure B-18. Peto-Prentice test for CTW:nonCTW+unk, 1961.

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 9 of 10
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Figure B-19. Peto-Prentice test for CTW:nonCTW+unk, 1962.

Figure B-20. Peto-Prentice test for CTW:nonCTW+unk, 1963.

ATTACHMENT B

PETO-PRENTICE PLOTS FOR CTW:NONCTW AND CTW:NONCTW+UNK COMPARISONS

Page 10 of 10